JP2009013186A - Coated phosphor particles, method for producing coated phosphor particles, phosphor-containing composition, light emitting device, image display device, and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated phosphor particle and a phosphor-containing composition that have good gas barrier properties and can improve the durability of a semiconductor light emitting device without aggregation of the phosphor.
SOLUTION: (A) phosphor particles coated with a glass composition containing one or more selected from (B) alkali metal, alkaline earth metal and Zn, wherein the glass composition The coated phosphor particles, wherein the yield point of the glass composition is 800 ° C. or less and / or the film thickness of the coating layer formed by the glass composition is 0.1 μm or more and 10 μm or less.
[Selection figure] None

Description

  The present invention relates to a coated phosphor particle, a method for producing the coated phosphor particle, a phosphor-containing composition using the coated phosphor particle, a light emitting device, and an image display device and an illumination device using the light emitting device. About. More specifically, the surface of the phosphor is coated with glass without agglomeration, and the coated phosphor particles have good gas barrier properties, the method for producing the coated phosphor particles, and the phosphor containing the coated phosphor particles. The present invention relates to a composition, a light emitting device, and an image display device and an illumination device using the light emitting device.

Conventionally, phosphors have been used industrially in large quantities for CRTs, fluorescent lamps, etc. However, in these applications, a method of using them as aqueous slurries when applying phosphors has been established industrially. Deteriorating phosphors could not be used.
On the other hand, in recent years, a technology for producing a white light emitting device by converting the wavelength of light emitted from a semiconductor light emitting chip with a phosphor has been put into practical use. Unlike the CRT and fluorescent lamp, the phosphor used here does not need to be an aqueous slurry in the manufacturing process. Therefore, if the light emission characteristics are excellent, even if some deterioration due to moisture is recognized, there may be no problem for short-term use by encapsulating the phosphor with the sealant.

However, for long-term use, there are many points that are insufficient in practicality, and countermeasures against deterioration of such phosphors due to moisture have been demanded. That is, the phosphors for semiconductor light emitting devices have a problem that they are gradually decomposed under high-temperature and high-humidity conditions or deteriorate due to lighting under high-temperature and high-humidity conditions.
In such a technical background, for the purpose of improving the moisture resistance of the phosphor particles, a method of coating the phosphor particles with an organic material, an inorganic material, a glass material, etc. (Patent Documents 1 to 3), the surface of the phosphor particles A method such as a method of coating a metal compound by a chemical vapor reaction method (Patent Document 4) and a method of attaching metal compound particles (Patent Document 5) are disclosed.
JP 2002-223008 A JP 2004-250705 A JP 2002-173675 A JP 2005-82788 A JP 2006-28458 A

However, further studies have been necessary to obtain a practical level of coated phosphor particles that can be used for a long period of time in semiconductor light emitting devices.
Moreover, the general method of glass material coating as described in Patent Documents 1 to 3, that is, when the coated phosphor particles are obtained by drying and heating the gelled layer formed on the phosphor particles to be densified. In some cases, phosphor particles may be aggregated and coated, which may cause problems with the uniformity and dispersibility of the phosphor particles. In addition, the chemical vapor reaction method of Patent Document 4 can be used when the glass to be coated has a single composition, but a glass composition composed of a plurality of components has different dense deposition conditions. It was difficult to form a coating layer.

  As a result of intensive studies in view of the above-mentioned problems, the present inventors have determined that the durability of the coated phosphor in a semiconductor light-emitting device is greater than the water resistance (water solubility) of the coated phosphor particles. Found that there is a tendency to depend on. Since the conventional coating layer has a certain degree of denseness, it can block liquid phase water having a certain viscosity, and has a certain effect in terms of imparting water resistance. However, it cannot be said that the denseness of the coating layer has reached a level that blocks the ingress of gas, and this is the reason that it does not reach a level that can actually be used for a long time in a semiconductor light emitting device. I found it. Moreover, since not only the above-mentioned water resistance but also oxygen permeability may be caused by the deterioration of the phosphor, it has been found that such a denseness as to have gas barrier properties is necessary.

  For example, in the method for obtaining coated phosphor particles by drying and heating the densified layer formed on the phosphor particles to obtain coated phosphor particles (the above-mentioned patent documents 1 to 3), the gelled layer is greatly contracted in the drying and heating process. However, since the film finally existing on the phosphor has some discontinuous portions, it is presumed that the gas barrier property is insufficient. In addition, it is difficult to form a dense coating layer having a high gas barrier property even when the surface of the phosphor particles is coated by a chemical vapor reaction method (Patent Document 4). It is estimated that a crack will occur. Further, it is presumed that the method of attaching metal compound particles (Patent Document 5) cannot ensure sufficient gas barrier properties because there are portions where particles are not attached.

Therefore, the inventors attach a specific glass powder selected according to the type of phosphor to the phosphor surface, rather than drying and heating the gelled layer formed on the phosphor. Then, by heating and then melting the glass powder, it was found that a continuous film could be formed on the phosphor, which solved the above problems, and the present invention was completed. Also, according to such a method,
It has also been found that agglomeration of phosphor particles can be suppressed and a good continuous film can be formed regardless of the type of phosphor.

That is, the gist of the present invention resides in the following [1] to [11].
[1] Coated phosphor particles obtained by coating (A) phosphor particles with a glass composition containing one or more selected from (B) alkali metal, alkaline earth metal and Zn, Coated phosphor particles having a yield point of 700 ° C. or lower (hereinafter, sometimes referred to as “coated phosphor particles of the first aspect of the present invention”).
[2] Coated phosphor particles obtained by coating (A) phosphor particles with (B) a glass composition containing one or more selected from alkali metals, alkaline earth metals and Zn, wherein (B) The thickness of the coating layer formed by the glass composition is 0.1 μm or more and 10 μm or less, and may be referred to as “coated phosphor particles of the second aspect of the present invention”. ). [3] The coated phosphor particle according to [1] or [2], wherein the (A) phosphor particle is a nitride and / or an oxide.
[4] The coated phosphor particles according to the above [1] to [3], wherein the glass composition (B) contains the following compounds (I) and (II).
(I) Glass formation with Zachariasen comprising one or more selected from SiO ₂ , B ₂ O ₃ , P ₂ O ₅ , GeO ₂ , TeO ₂ , Al ₂ O ₃ , Ga ₂ O ₃ , and Bi ₂ O ₃ Oxide (II) Network-modified oxide containing one or more selected from alkali metal atoms, alkaline earth metal atoms, and Zn [5] The lead content in the glass composition (B) is 0.1% by weight The coated phosphor particles according to [1] to [4] above.
[6] The coated phosphor particle according to [1] to [5], wherein the coating layer formed by the glass composition (B) is a continuous film.
[7] (A) phosphor particles, and (B) a glass composition containing one or more selected from alkali metals, alkaline earth metals and Zn are mixed, and the above-mentioned (B) yield point or more of the glass composition A method for producing coated phosphor particles, characterized by heating with
[8] A phosphor-containing composition comprising the coated phosphor particles according to [1] to [6].
[9] A light-emitting device formed using the coated phosphor particles according to [1] to [6].
[10] An image display device comprising the light-emitting device according to [9] as a light source.
[11] An illumination device comprising the light-emitting device according to [9] as a light source.

  According to the present invention, it is possible to provide a coated phosphor particle and a phosphor-containing composition that have good gas barrier properties and can improve the durability of a semiconductor light-emitting device without aggregation of the phosphor. Further, by using the coated phosphor particles, it is possible to provide a light emitting device with excellent durability that can be used for a long period of time, and an image display device and an illumination device using the light emitting device.

Hereinafter, although each element of this invention is demonstrated in detail, this invention is not limited to the following description, It can implement in various changes within the range of the summary.
[1] (A) Phosphor Particles There are no particular limitations on the phosphor particles (hereinafter also referred to as “phosphors” as appropriate) that are the targets of the surface treatment method of the present invention, but they have excellent light emission characteristics. Phosphor particles with low moisture resistance, phosphor particles that are easily degraded by exposure to oxygen, phosphor particles that are susceptible to ion elution, phosphor particles that are susceptible to degradation by electrolysis, phosphor particles with odor, etc. The surface treatment method of the present invention is preferable because it can be preferably used for a light emitting device or the like. That is, the gas barrier property is ensured by the surface treatment of the present invention, and water vapor, oxygen and odor-causing substances are blocked. Further, deterioration of peripheral members such as a package and a sealing material due to elution of ions derived from the phosphor is suppressed. Moreover, deterioration of the phosphor due to leakage current can be suppressed. Hereinafter, specific examples of the phosphor are illustrated, but in the illustrated general formula, phosphors that are different only in a part of the structure are appropriately omitted. For example, “Y ₂ SiO ₅ : Ce ³⁺ ”, “Y ₂ SiO ₅ : Tb ³⁺ ” and “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ” are changed to “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ”, “ “La ₂ O ₂ S: Eu”, “Y ₂ O ₂ S: Eu” and “(La, Y) ₂ O ₂ S: Eu” are collectively shown as “(La, Y) ₂ O ₂ S: Eu”. ing. Omitted parts are shown separated by commas (,).

[1-1] Preferred phosphor particles
Preferred phosphors for use in the coating treatment method of the present invention include inorganic phosphors and organic phosphors.
As the inorganic phosphor, for example, a group consisting of M ₃ SiO ₅ , MS, MGa ₂ S ₄ , MAlSiN ₃ , M ₂ Si ₅ N ₈ , MSi ₂ N ₂ O ₂ as a base crystal (where M is Ca, Sr , Ba represents at least one selected from the group consisting of Ba, and an activator is Cr, Mn, Fe, Bi, Ce, Pr, Nd, Sm, Eu, Tb. , Dy, Ho, Er, Tm, and a phosphor containing at least one of Yb.

Specific examples of the phosphor include, for example, Ba ₃ SiO ₅ : Eu, (Sr _{1 -a} Ba _a ) ₃ SiO ₅ : Eu, Sr ₃ SiO ₅ : Eu, CaS: Eu, SrS: Eu, BaS: Eu. _{, CaS: Ce, SrS: Ce} , BaS: Ce, CaGa 2 S 4: Eu, SrGa 2 S 4: Eu, BaGa 2 S 4: Eu, CaGa 2 S 4: Ce, SrGa 2 S 4: Ce, BaGa 2 _{S 4: Ce, CaAlSiN 3:} Eu, SrAlSiN 3: Eu, (Ca 1-a Sr a) AlSiN 3: Eu, CaAlSiN 3: Ce, SrAlSiN 3: Ce, (Ca 1-a Sr a) AlSiN 3: Ce _{, Ca 2 Si 5 N 8:} Eu, Sr 2 Si 5 N 8: Eu, Ba 2 Si 5 N 8: Eu, (Ca 1-a Sr a) 2 Si 5 N 8: E _{, Ca 2 Si 5 N 8:} Ce, Sr 2 Si 5 N 8: Ce, Ba 2 Si 5 N 8: Ce, (Ca 1-a Sr a) 2 Si 5 N 8: Ce, CaSi 2 N 2 O 2 _{: Eu, SrSi 2 N 2 O} 2: Eu, BaSi 2 N 2 O 2: Eu, CaSi 2 N 2 O 2: Ce, SrSi 2 N 2 O 2: Ce, BaSi 2 N 2 O 2: Ce, (Ba , Sr, Ca) ₂ SiO ₄ : Eu, Ba ₃ Si ₆ O ₉ N ₄ : Eu (in relation to the above, a satisfies 0 ≦ a ≦ 1).
Among them, CaS, CaGa ₂ S ₄ : Eu, SrGa ₂ S ₄ : Eu, (Sr _0.8 Ca _0.2 ) AlSiN ₃ : Eu, (Ba, Sr, Ca) ₂ SiO ₄ : Eu, Ba ₃ Si ₆ Preferred examples include O ₉ N ₄ : Eu and (Sr, Ca) AlSiN ₃ : Eu.

[1-2] Other phosphor particles
In addition to the above phosphors, other phosphors can be used depending on the purpose, such as improved durability and improved dispersibility.
The composition of the phosphor is not particularly limited, but a metal oxide represented by Y ₂ O ₃ , Zn ₂ SiO ₄ or the like that is a crystal matrix, a metal nitride represented by Sr ₂ Si ₅ N ₈ or the like, Ca ₅ (PO
_{4) 3} Cl or the like phosphate and ZnS typified, SrS, a sulfide typified by CaS, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb A combination of rare earth metal ions such as Ag, Cu, Au, Al, Mn, Sb and the like as activators or coactivators is preferred.

Preferred examples of the crystal matrix include sulfides such as (Zn, Cd) S, SrGa ₂ S ₄ , SrS, and ZnS, oxysulfides such as Y ₂ O ₂ S, and (Y, Gd) ₃ Al ₅ O. _{12, YAlO 3, BaMgAl 10 O} 17, (Ba, Sr) (Mg, Mn) Al 10 O 17, (Ba, Sr, C
a) (Mg, Zn, Mn ) Al 10 O 17, BaAl 12 O 19, CeMgAl 11 O 19
, (Ba, Sr, Mg) O.Al ₂ O ₃ , BaAl ₂ Si ₂ O ₈ , SrAl ₂ O ₄ , Sr ₄ Al ₁₄ O ₂₅ , Y ₃ Al ₅ O _12, etc., aluminates such as Y ₂ SiO ₅ Silicate such as Zn ₂ SiO ₄ , oxide such as SnO ₂ and Y ₂ O ₃ , borate such as GdMgB ₅ O ₁₀ and (Y, Gd) BO ₃ , Ca ₁₀ (PO ₄ ) ₆ (F, Cl ) ₂ , halophosphates such as (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ , phosphates such as Sr ₂ P ₂ O ₇ , (La, Ce) PO _4, etc. it can.

However, the crystal matrix and the activator element or coactivator element are not particularly limited in element composition, and can be partially replaced with elements of the same family, and the obtained phosphor is light in the near ultraviolet to visible region. Any material that absorbs and emits visible light can be used.
Specifically, the following phosphors can be used, but these are merely examples, and phosphors that can be used in the present invention are not limited to these.

[1-2-1] Orange to red phosphor
Examples of phosphors that emit orange to red fluorescence (hereinafter appropriately referred to as “orange to red phosphors”) include the following. The emission peak wavelength of the orange to red phosphor is preferably in the wavelength range of usually 580 nm or more, preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less. Examples of such orange to red phosphors include europium composed of broken particles having a red fracture surface and emitting red region (Mg, Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu. The activated alkaline earth silicon nitride phosphor is composed of growing particles having a substantially spherical shape as a regular crystal growth shape, and emits light in the red region (Y, La, Gd, Lu) ₂ O ₂ S: Examples include europium activated rare earth oxychalcogenide phosphors represented by Eu. Furthermore, the oxynitride and / or acid containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A No. 2004-300247 A phosphor containing a sulfide and containing an oxynitride having an alpha sialon structure in which a part or all of the Al element is substituted with a Ga element can also be used in this embodiment. These are phosphors containing oxynitride and / or oxysulfide.

Also, other examples of the red _{phosphor, (La, Y) 2 O} 2 S: Eu Tsukekatsusan sulfide phosphor such as _{Eu, Y (V, P)} O 4: Eu, Y 2 O 3: Eu , etc. Eu-activated oxide _{phosphor, (Ba, Sr, Ca,} Mg) 2 SiO 4: Eu, Mn, (Ba, Mg) 2 SiO 4: Eu, Eu such as Mn, Mn-activated silicate phosphor, Eu-activated tungstate phosphors such as LiW ₂ O ₈ : Eu, LiW ₂ O ₈ : Eu, Sm, Eu ₂ W ₂ O ₉ , Eu ₂ W ₂ O ₉ : Nb, Eu ₂ W ₂ O ₉ : Sm (Ca, Sr) S: Eu-activated sulfide phosphors such as Eu, YAlO ₃ : Eu-activated aluminate phosphors such as Eu, LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu, Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ : Eu, (Sr, Ba, Ca) ₃ SiO ₅ : Eu, Sr ₂ Ba-activated silicate phosphors such as BaSiO ₅ : Eu, (Y, Gd) ₃ Al ₅ O ₁₂ : Ce, (Tb, Gd) ₃ Al ₅ O ₁₂ : Ce-activated aluminate phosphors such as Ce, _{(Mg, Ca, Sr, Ba} ) 2 Si 5 N 8: Eu, (Mg, Ca, Sr, Ba) SiN 2: Eu, (Mg, Ca, Sr, Ba) AlSiN 3: Eu -activated nitride such as Eu Phosphors, Ce-activated nitride phosphors such as (Mg, Ca, Sr, Ba) AlSiN ₃ : Ce, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn, etc. Eu, Mn-activated halophosphate phosphor, Ba ₃ MgSi ₂ O ₈ : Eu, Mn, (Ba, Sr, Ca, Mg) ₃ (Zn, Mg) Si ₂ O ₈ : Eu, Mn, etc. activated silicate phosphor, 3.5MgO · 0.5MgF ₂ · Ge _2: Mn activated germanate salt phosphors such as Mn, Eu Tsukekatsusan nitride phosphor such as Eu-activated _{α-sialon, (Gd, Y, Lu,} La) 2 O 3: Eu, Bi, etc. Eu, Bi-activated oxide phosphor, (Gd, Y, Lu, La) ₂ O ₂ S: Eu, Bi-activated oxysulfide phosphor such as Eu, Bi, (Gd, Y, Lu, La) VO ₄ : Eu, Bi activated vanadate phosphors such as Eu, Bi, etc., SrY ₂ S ₄ : Eu, Ce activated sulfide phosphors such as Eu, Ce, etc., Ce activated sulfide fluorescence such as CaLa ₂ S ₄ : Ce, etc. (Ba, Sr, Ca) MgP ₂ O ₇ : Eu, Mn, (Sr, Ca, Ba, Mg, Zn) ₂ P ₂ O ₇ : Eu, Mn-activated phosphate phosphors such as Eu and Mn , (Y, Lu) ₂ WO ₆ : Eu, Mo-activated tungstate phosphor such as Eu, Mo, (Ba, Sr, Ca) _x Si _y Nz: Eu, Ce (where x, y, z represent an integer of 1 or more. Eu, Ce activated nitride phosphors such as (Ca, Sr, Ba, Mg) ₁₀ (PO ₄ ) ₆ (F, Cl, Br, OH) ₂ : Eu, Mn activated halophosphorus such as Eu, Mn Acid salt phosphor, ((Y, Lu, Gd, Tb) _1-xy Sc _x Ce _y ) ₂ (Ca, Mg) _1-r (Mg, Zn) _{2 + r} Siz _-q Ge _q O _{12 + δ} It is also possible to use a Ce-activated silicate phosphor or the like.

  Examples of red phosphors include β-diketonates, β-diketones, aromatic carboxylic acids, red organic phosphors composed of rare earth element ion complexes having an anion such as Bronsted acid as a ligand, and perylene pigments (for example, Dibenzo {[f, f ′]-4,4 ′, 7,7′-tetraphenyl} diindeno [1,2,3-cd: 1 ′, 2 ′, 3′-lm] perylene), anthraquinone pigment, Lake pigments, azo pigments, quinacridone pigments, anthracene pigments, isoindoline pigments, isoindolinone pigments, phthalocyanine pigments, triphenylmethane basic dyes, indanthrone pigments, indophenol pigments, It is also possible to use a cyanine pigment or a dioxazine pigment.

Of the red phosphors, those having a peak wavelength in the range of 580 nm or more, preferably 590 nm or more, and 620 nm or less, preferably 610 nm or less can be suitably used as the orange phosphor. Examples of such orange phosphors include Eu-activated silicate phosphors such as (Sr, Ba, Ca) ₃ SiO ₅ : Eu, Sr ₂ BaSiO ₅ : Eu, (Sr, Mg) ₃ (PO ₄ ). ₂ : Sn-activated phosphate phosphors such as Sn ^{2+ and the} like.

Any one of the red phosphors exemplified above may be used alone, or two or more may be used in any combination and ratio.
Among the above examples, as the red phosphor, (Ca, Sr, Ba) AlSiN ₃ : Eu, (Ca, Sr, Ba) AlSiN ₃ : Ce, (La, Y) ₂ O ₂ S: Eu are preferable, (Sr, Ca) AlSiN ₃ : Eu and (La, Y) ₂ O ₂ S: Eu are particularly preferable.
Moreover, among the above examples, (Sr, Ba) ₃ SiO ₅ : Eu is preferable as the orange phosphor.

[1-2-2] Green phosphor
Examples of phosphors that emit green fluorescence (hereinafter referred to as “green phosphors” as appropriate) include the following. The emission peak wavelength of the green phosphor is usually 490 nm or more, preferably 510 nm or more, more preferably 515 nm or more, and usually 560 nm or less, preferably
Is preferably in the wavelength range of 540 nm or less, more preferably 535 nm or less.

As such a green phosphor, for example, a europium-activated alkali represented by (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu that is composed of fractured particles having a fracture surface and emits light in the green region. Europium-activated alkaline earth silicate composed of an earth silicon oxynitride phosphor, broken particles having a fracture surface, and emitting green light (Ba, Ca, Sr, Mg) ₂ SiO ₄ : Eu System phosphors and the like.

Other green phosphors include Eu-activated aluminate phosphors such as Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, and (Sr, Ba) Al _2. Si ₂ O ₈ : Eu, (Ba, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu, (Ba, Ca, Sr, Mg) ₉ (Sc, Y, Lu, Gd) ₂ (Si, Ge) ₆ O ₂₄ : Eu-activated silicate phosphor such as Eu, Y ₂ SiO ₅ : Ce, Ce, Tb-activated silicate phosphors such as Tb, Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu-activated borate phosphate phosphors such as Eu, Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu-activated halo silicate phosphor such as _Eu, Zn 2 _SiO 4: M such as Mn Activated silicate _{phosphors, CeMgAl 11 O 19: Tb,} Y 3 Al 5 O 12: Tb -activated aluminate phosphors such as _{Tb, Ca 2 Y 8 (SiO} 4) 6 O 2: Tb, La 3 Ga ₅ SiO _14: Tb-activated silicate phosphors such as _{Tb, (Sr, Ba, Ca} ) Ga 2 S 4: Eu, Tb, Eu and Sm and the like, Tb, Sm-activated thiogallate _phosphor, Y 3 _(Al, Ga) ₅ O ₁₂ : Ce, (Y, Ga, Tb, La, Sm, Pr, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce activated silicate phosphor such as Ce, Ce activated oxide phosphor such as CaSc ₂ O ₄ : Ce, SrSi ₂ O ₂ N ₂ : Eu, (Mg, Sr, B a, Ca) Si ₂ O ₂ N ₂ : Eu, Eu-activated oxynitride phosphors such as Eu-activated β sialon, BaMgAl ₁₀ O ₁₇ : Eu, Mn-activated aluminate phosphors such as Eu and Mn, Eu-activated aluminate phosphors such as SrAl ₂ O ₄ : Eu, Tb-activated oxysulfide phosphors such as (La, Gd, Y) ₂ O ₂ S: Tb, and Ce such as LaPO ₄ : Ce, Tb , Tb-activated phosphate phosphors, sulfide phosphors such as ZnS: Cu, Al, ZnS: Cu, Au, Al, (Y, Ga, Lu, Sc, La) BO ₃ : Ce, Tb, Na ₂ Gd ₂ B ₂ O ₇ : Ce, Tb, (Ba, Sr) ₂ (Ca, Mg, Zn) B ₂ O ₆ : Ce, Tb activated borate phosphor such as K, Ce, Tb, Ca ₈ Mg ( SiO ₄ ) ₄ Cl ₂ : Eu, Mn activated halosilicate phosphor such as Eu, Mn, ( Sr, Ca, Ba) (Al, Ga, In) ₂ S ₄ : Eu-activated thioaluminate phosphor such as Eu, thiogallate phosphor, (Ca, Sr) ₈ (Mg, Zn) (SiO ₄ ) ₄ Cl _2: Eu, Eu such as Mn, Mn-activated halo silicate _{phosphor, MSi 2 O 2 N 2:} Eu, M 3 Si 6 O 9 N 4: Eu, M 2 Si 7 O 10 N 4: Eu ( where , M represents an alkaline earth metal element. It is also possible to use Eu-activated oxynitride phosphors such as
In addition, as the green phosphor, it is also possible to use a pyridine-phthalimide condensed derivative, a benzoxazinone-based, a quinazolinone-based, a coumarin-based, a quinophthalone-based, a nartaric imide-based fluorescent dye, or an organic phosphor such as a terbium complex. is there.

[1-2-3] Blue phosphor
Examples of phosphors emitting blue fluorescence (hereinafter referred to as “blue phosphors” as appropriate) include:
Things. The emission peak wavelength of the blue phosphor is usually 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, preferably 470 nm or less, more preferably 460 nm or less. .

As such a blue phosphor, a europium-activated barium magnesium aluminate system represented by BaMgAl ₁₀ O ₁₇ : Eu composed of growing particles having a substantially hexagonal shape as a regular crystal growth shape and emitting light in a blue region. Europium activated halo represented by (Ca, Sr, Ba) ₅ (PO ₄ ) ₃ Cl: Eu, which is composed of phosphors and growing particles having a substantially spherical shape as a regular crystal growth shape, and emits light in a blue region. Calcium phosphate phosphor, composed of growing particles having a substantially cubic shape as a regular crystal growth shape, emits light in the blue region, and is activated by europium represented by (Ca, Sr, Ba) ₂ B ₅ O ₉ Cl: Eu Consists of alkaline earth chloroborate phosphors, fractured particles with fractured surfaces, and light emission in the blue-green region And (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu are europium activated alkaline earth aluminate phosphors.

Other blue phosphors include Sn-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Sn, (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba). ₄ Al ₁₄ O ₂₅ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, BaAl ₈ O ₁₃ : Eu-activated aluminate phosphors such as Eu, SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce-activated such as Ce Thiogallate phosphor, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu-activated aluminate phosphor such as Eu, Tb, Sm, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn activated aluminate phosphor such as Eu, Mn, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba, Sr, Ca) ₅ (PO ₄ ) ₃ (Cl, F, Br, OH): Eu , Mn, Eu -activated halophosphate phosphors such as _{Sb, BaAl 2 Si 2 O 8} : Eu, (Sr, Ba) 3 MgSi 2 O 8: Eu -activated silicate such as Eu Salt phosphors, Eu-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Eu, sulfide phosphors such as ZnS: Ag, ZnS: Ag, Al, and Ce-activated such as Y ₂ SiO ₅ : Ce Silicate phosphor, tungstate phosphor such as CaWO ₄ , (Ba, Sr, Ca) BPO ₅ : Eu, Mn, (Sr, Ca) ₁₀ (PO ₄ ) ₆ .nB ₂ O ₃ : Eu, 2SrO. 0.84P ₂ O ₅ .0.16B ₂ O ₃ : Eu, Mn-activated borate phosphate phosphor such as Eu, Eu-activated halosilicate phosphor such as Sr ₂ Si ₃ O ₈ · 2SrCl ₂ : Eu Etc. can also be used.

Further, as the blue phosphor, for example, naphthalic acid imide-based, benzoxazole-based, styryl-based, coumarin-based, pyrazoline-based, triazole-based fluorescent dyes, organic phosphors such as thulium complexes, and the like can be used. . Among the above examples, as the blue phosphor, BaMgAl ₁₀ O ₁₇ : Eu, (Ba, Ca, Mg) ₂ SiO ₄ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu is preferred, and BaMgAl ₁₀ O ₁₇ : Eu is particularly preferred.

[1-2-4] Yellow phosphor
Examples of the phosphor that emits yellow fluorescence (hereinafter, appropriately referred to as “yellow phosphor”) include the following. The emission peak wavelength of the yellow phosphor is usually in the wavelength range of 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. .

Examples of such yellow phosphors include various oxide-based, nitride-based, oxynitride-based, sulfide-based, and oxysulfide-based phosphors.
In particular, RE ₃ M ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, and Sm, and M represents Al, Ga, and Sc. And M ^a ₃ M ^b ₂ M ^c ₃ O ₁₂ : Ce (where M ^a is a divalent metal element and M ^b is a trivalent metal element) , ^{M c} represents a tetravalent metal element) garnet phosphor having a garnet structure represented by ^{_{like, AE 2 M d O 4:}} . Eu ( where, AE is, Ba, Sr, Ca, Mg , and An orthosilicate phosphor represented by at least one element selected from the group consisting of Zn, M ^d represents Si and / or Ge, and the like, oxygen of constituent elements of the phosphors of these systems Acid in which a part of Compound phosphor, AEAlSiN _3: Ce (., Where, AE is, Ba, Sr, Ca, represents at least one element selected from the group consisting of Mg and Zn) nitride having CaAlSiN ₃ structures such as system Examples thereof include phosphors activated with Ce such as phosphors.

In addition, as yellow phosphors, sulfide-based fluorescence such as CaGa ₂ S ₄ : Eu, (Ca, Sr) Ga ₂ S ₄ : Eu, (Ca, Sr) (Ga, Al) ₂ S ₄ : Eu, etc. It is also possible to use a phosphor activated by Eu, such as an oxynitride phosphor having a SiAlON structure such as a body, Cax (Si, Al) ₁₂ (O, N) ₁₆ : Eu. Examples of yellow phosphors include fluorescent dyes such as brilliant sulfoflavine FF (Colour Index Number 56205), basic yellow HG (Colour Index Number 46040), eosine (Colour Index Number 45380), and rhodamine 6G (Colour Index Number 45160). Etc. can also be used.

[1-4] Physical properties of phosphor particles
There is no particular limitation on the particle size of the phosphors used in the phosphor of the present invention, the median particle diameter (D ₅₀₎ in a conventional 0.1μm or more, preferably 2μm or more, more preferably 10μm or more. Moreover, it is 100 micrometers or less normally, Preferably it is 50 micrometers or less, More preferably, it is 25 micrometers or less. If D ₅₀ is too small, and the luminance decreases, there is a possibility that phosphor particles tend to aggregate. On the other hand, when D ₅₀ is too large, there is a possibility that clogging of such coating unevenness or dispenser may occur.

  The particle size distribution (QD) of the phosphor particles is preferably small in order to align the dispersed state of the particles in the phosphor-containing composition, but in order to reduce the particle size, the classification yield decreases, leading to an increase in cost. Usually, it is 0.03 or more, preferably 0.05 or more, more preferably 0.07 or more. Moreover, it is 0.4 or less normally, Preferably it is 0.3 or less, More preferably, it is 0.2 or less. Further, the shape of the phosphor particles is not particularly limited.

In the present invention, the median particle size (D ₅₀ ) and particle size distribution (QD) can be obtained from a weight-based particle size distribution curve. The weight-based particle size distribution curve is obtained by measuring the particle size distribution by a laser diffraction / scattering method, and specifically, for example, can be measured as follows.
A phosphor is dispersed in a solvent such as ethylene glycol under an environment of an air temperature of 25 ° C. and a humidity of 70%.

Measurement is performed with a laser diffraction particle size distribution measuring apparatus (Horiba, Ltd. LA-300) in a particle size range of 0.1 μm to 600 μm.
Integrated value in the weight particle size distribution curve is denoted a particle size value when the 50% and median particle diameter D _50. Further, the particle size values when the integrated values are 25% and 75% are expressed as D ₂₅ and D ₇₅ , respectively, and defined as QD = (D ₇₅ −D ₂₅ ) / (D ₇₅ + D ₂₅ ). A small QD means a narrow particle size distribution.

[1-5] Phosphor surface treatment
The phosphor particles used in the present invention may be further subjected to a surface treatment for the purpose of improving water resistance.
As an example of such a surface treatment, for example, as described in JP-T-2006-523245, the phosphor particles are subjected to a heat treatment to chemically modify the original components of the phosphor particles. Known surface treatments such as forming a coating may be mentioned.
Further, a surface treatment for coating a metal phosphate is also effective. Specifically, for example, a surface treatment method that can be performed by the following procedures (i) to (iii) can be given. (I) A predetermined amount of a water-soluble phosphate such as potassium phosphate and sodium phosphate and at least one of alkaline earth metals such as calcium chloride, strontium sulfate, manganese chloride and zinc nitrate, Zn and Mn A water-soluble metal salt compound is added to the phosphor suspension and stirred. (Ii) A phosphate of at least one metal among alkaline earth metals, Zn and Mn is formed in the suspension, and the generated metal phosphate is deposited on the phosphor surface. (Iii) Remove moisture.

[2] (B) Glass Composition [2-1] Preferred Glass Composition The glass composition used in the present invention contains one or more selected from alkali metals, alkaline earth metals and Zn. Preferably, the following compounds (I) and (II) are contained.
(I) Glass formation with Zachariasen comprising one or more selected from SiO ₂ , B ₂ O ₃ , P ₂ O ₅ , GeO ₂ , TeO ₂ , Al ₂ O ₃ , Ga ₂ O ₃ , and Bi ₂ O ₃ Oxide (II) Network-modified oxide containing one or more selected from alkali metal atoms, alkaline earth metal atoms, and Zn “Glass-forming oxide by Zachariasen” in the component (I) is a non-patent document W. H. Zachariasen, J. Am. Chem. Soc., 54, 3841-3851 (1932), a glass-forming oxide that is the basic skeleton of glass. Among _these, preferably glass forming oxides including _{SiO 2, B 2 O 3,} P 2 O 5, Al 2 O 3, Al 2 O 3, glass-forming oxides containing SiO _2, P 2 _{O 5} is Particularly preferred are those containing both Al ₂ O ₃ and P ₂ O ₅ .

  The blending amount of the component (I) is usually 20% by weight or more, preferably 30% by weight or more, more preferably 33% by weight or more, and usually 90% by weight or less, preferably 80% with respect to the whole glass composition. % By weight or less, more preferably 70% by weight or less. If the blending amount of the component (I) is too small, the mechanical strength may be lowered or the water resistance may be poor. If it is too much, the yield point may be increased.

In the present invention, (II) a network-modified oxide containing one or more selected from an alkali metal atom, an alkaline earth metal atom, and Zn serves to lower the yield point or improve the durability. is there. Among these, a network modification oxide containing BaO, SrO, ZnO, Li ₂ O, Na ₂ O, K ₂ O, and MgO is preferable, and a network containing Li ₂ O, Na ₂ O, K ₂ O, ZnO, and CaO is preferable. Modified oxides are particularly preferred.

  The amount of the component (II) is usually 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, and usually 80% by weight or less, preferably 70%, based on the entire glass composition. % By weight or less, more preferably 67% by weight or less. If the amount of the component (II) is too large, the durability may decrease, and if it is too small, the yield point may increase.

Examples of the combination of (I) and (II), and a combination of network-modifying oxide containing glass-forming oxides and Na ₂ O including, for example, _P 2 _{O 5.}
The weight ratio of (I) and (II) is usually 90:10 to 20:80, preferably 80:20 to 20:80.
In the coated phosphor particles of the first invention, the yield point of the glass composition is 700 ° C. or lower, preferably 650 ° C. or lower, more preferably 600 ° C. or lower. Moreover, it is 100 degreeC or more normally, Preferably it is 200 degreeC or more, More preferably, it is 250 degreeC or more. If the yield point is too large, it will become too hot when it is melted and coated, and the phosphor itself may deteriorate, or the phosphor's luminescent properties may deteriorate due to the reaction between the phosphor and the glass composition. And the stability of the coating is reduced.

Further, the so-called low melting point glass having a low yield point in the coated phosphor particles of the present invention is preferably a phosphoric acid-based (containing P ₂ O ₅ ) glass composition.
Further, it is more preferable to contain a fluorine atom for the purpose of reducing the yield point of the glass and improving the durability. Even if the fluorine atom is not contained in the glass, it is AlF ₃ , LiF, NaF, CaF ₂ , SrF ₂ , BaF ₂ , ZnF ₂ , MgF ₂ when the glass composition is coated (at the time of raw material mixing and / or melting). You may add fluorine compounds, such as.

  In addition to the effects of lowering the yield point and improving the durability of the glass composition, the fluorine atom is presumed to have the effect of improving the affinity with the phosphor surface. That is, it is speculated that there is an interface layer forming function for matching and adhesion of the expansion coefficient between the phosphor and the glass. Since adhesion is increased at the interface between the phosphor and the glass layer, it is estimated that at least a part of the glass component penetrates from the interface between the phosphor and the glass. It is speculated that fluoride ions promote this penetration. As long as the affinity with the phosphor surface increases, the type of additive is not limited, and chlorine, iodine, and bromine can be used, but fluorine is preferred from the viewpoint of stability.

The glass composition in the coated phosphor particles of the present invention has a lead content of usually 0.1% by weight or less, preferably 0.01% by weight or less, more preferably 0.001% by weight or less. The lead content is preferably as low as possible. If it is too high, there is a possibility of contamination by harmful elements during disposal.
Preferable specific examples of the glass composition in the coated phosphor particles of the present invention include, for example, P ₂ O ₅ of 34 wt% to 50 wt%, Li ₂ O of 2 wt% to 9 wt%, and Na ₂ O of 7 wt% to 28 wt%, R ₂ O (where R is an alkali metal) is 17 wt% to 41 wt%, Al ₂ O ₃ is 6.5 wt% to 30 wt%, and ZnO is 0 wt% % To 22% by weight, BaO from 0% to 21% by weight, SrO from 0% to 18% by weight, CaO from 0% to 16% by weight, RO (where R is an alkaline earth metal) ) Is from 0% by weight to 34% by weight, and F is from 0% by weight to 32% by weight. R ₂ O is preferably, _{K 2} O, and the like, is preferably 3 wt% or more 27 wt% or less. RO is preferably MgO, and preferably 0 wt% or more and 14 wt% or less. F is preferably 1.5-32%.

Known glass compositions can be used for the glass composition used in the present invention. Examples thereof include known glass compositions described in International Publication No. 2003/037813, JP-A No. 2003-26439, and JP-A No. 5-199379.
Moreover, a commercially available glass composition can be used. Specifically, “K-PG325”, “K-PG375” manufactured by Sumita Optical Glass Co., Ltd. described in OPTICAL GLASS DATA BOOK (Version 5.00 issued on April 28, 2005, revised on July 5, 2005), “K-PG395”, “K-PMK10”, “K-PMK10”, “K-PSKn2”, “K-BK7”, “K-BPG2”, “K-SKF6”, “K-LaK7”, “K -CaFK95 "," K-PFK85 "," K-PFK80 "," K-GFK70 "," K-GFK68 "," K-CD45 "," K-CD120 "," K-LaFK55 "," K-LaFK60 " ”,“ K-PSK200 ”,“ K-PSFn1 ”,“ K-PSFn2 ”,“ K-PSFn3 ”,“ K-PSFn4 ”,“ K-PSFn5 ”,“ K-PMK1 ” ”,“ K-PSK100 ”,“ K-VC80 ”,“ K-VC81 ”,“ K-VC82 ”,“ K-VC89 ”,“ P-SK5S ”,“ P-SK12S ”,“ P ”manufactured by Hikari Glass Co., Ltd. -LAK13S "," P-LAF010S "," P-FKH2S "," P-LASF03S "," P-FK01S ", Asahi Fiber Glass" ZP150 ", Asahi Techno Glass" SK-231 "," SK -360 "," K801 "," K805 "," K806 "," K807 "," K808 "," LS-5 "," BS-7 "," FF201 "," FF209 ", 2007 ASF for Asahi Glass Electronics “IWF-7574”, “FF201”, “FF209”, “K301”, “K303”, “K30” manufactured by Asahi Glass Co., Ltd. ”,“ K805 ”,“ K807 ”,“ K808 ”,“ K834 ”,“ K835 ”,“ K836 ”,“ LS-5 ”,“ KF9079 ”,“ ASF1495 ”,“ ASF1560 ”,“ ASF1561 ”,“ ASF1620B ” "," ASF1620M "," ASF1700 "," ASF1702 "," ASF1710 "," ASF1765B "," ASF1768 "," ASF1771 "," ASF1800 "," ASF1891 "," ASF1891F "," ASF1898 "," ASF1939 " “ASF1941”, “ASF1941B”, “developed product 1991” and the like can be mentioned.

Examples of the glass that can be used for the glass coating of the present invention include Bi ₂ O ₃ —SiO ₂ —B ₂ O ₃ glass having a glass softening point of around 550 ° C., and a glass transition point of about 500 to 700. SiO ₂ —B ₂ O ₃ —R ₂ O, SiO ₂ —B ₂ O ₃ —RO—R ₂ O-based glass (wherein R represents an alkali metal or an alkaline earth metal) at a temperature of 0 ° C. was used. Examples include lead-free glass ceramics.

In addition, focusing on the applications that have been used in the past, Bi used as an additive for lowering the sintering temperature of glass, ceramics, powdered glass used for adhesion and sealing, various ceramics, and metal powder. _{2 O 3 -B 2 O 3 -SiO} 2, B 2 O 3 -ZnO, SiO 2 -B 2 O 3 -R 2 O, powdered glass such as SiO ₂ -B ₂ O 3 -RO based (wherein, _{R 2} O represents an alkali metal oxide, and RO represents an alkaline earth metal oxide.).

Hereinafter, further detailed examples will be given focusing on the constituent elements of the glass.
The glass preferably used in the present invention is a non-Pb-containing low-melting glass, and this glass is a conventional Pb-containing low-melting glass, in which Pb is replaced with Bi, Zn or Sn.
Non-Pb conversion is achieved by adopting a method such as changing the basic composition of glass to phosphate glass, increasing the alkali / boric acid component, and introducing fluoride.

Examples of bismuth (Bi) -introduced glass include Bi ₂ O ₃ —B ₂ O ₃ -based glass compositions. _{Specifically, 37Bi 2 O 3 -39.3B 2 O} 3 -7.2BaO-16.7CuO, 65Bi 2 O 3 -25ZnO-7.5B 2 O 3 -2.0Al 2 O 3, Bi 2 O 3
Bi ₂ O ₃ —ZnO—B ₂ O ₃ -based glass composition containing 27 wt% or more and 55 wt% or less, Bi ₂ O ₃ —SiO ₂ -based crystallized glass powder (Bi ₂ O ₃ content is 50 -62 _{wt%), SiO 2 -B 2 O} 3 -Bi 2 O 3 -ZnO based glass composition, and the like.

As an example of phosphate glass, phosphate glass is preferably used because it has high solubility in other components and has a low melting temperature. As a specific example, P ₂ O ₅ : Na ₂ O: CaO
_{: BaO: Al 2 O 3:} B 2 O 3 = 30~40: 10~20: 10~20: 10~20: 2~8: mention may be made of 1-5 glass composition.
Addition of alumina is effective in improving chemical durability, but it may negatively affect low melting point. SnO 2 is added based on phosphate glass, and B ₂ O ₃ or SiO ₂ , which is a normal glass forming oxide, may be added. P ₂ O ₅ —SnO ₂ glass composition, P ₂ O ₅ —SnO—B ₂ O ₃ glass composition, and P ₂ O ₅ —SnO—SiO ₂ glass composition can be exemplified. In addition, a CuO—P ₂ O ₅ —RO-based glass composition (where R represents any one of Zn, Ba, Ca, Mg, Sr, Sn, Ni, Fe, and Mn) can be given. In addition, P ₂ O ₅ —ZnO—SnO—R ₂ O—RO (where R ₂ O represents an alkali metal oxide, and RO represents an alkaline earth metal oxide), SrO—ZnO—P ₂ O ₅ , 10SrO-50ZnO-40P ₂ O ₅ glass composition.

Examples of alkali borosilicate glass include R ₂ O—RO—B ₂ O ₃ —SiO ₂ glass composition (where R ₂ O is an alkali metal oxide, RO is an alkaline earth metal oxide) Is shown.). Specifically, B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —ZrO ₂ glass composition, SiO ₂ —B ₂ O ₃ —ZnO—R ₂ O—RO glass composition (provided that R ₂ O Is an alkali metal oxide, RO is an alkaline earth metal oxide), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —RO—R ₂ O glass composition (where R ₂ O is , Alkali metal oxides, and RO are alkaline earth metal oxides).

In the coated phosphor particles of the second invention, the coating layer formed by the glass composition has a film thickness of 0.1 μm or more, preferably 0.5 μm or more, 10 μm or less, preferably 5 μm or less, More preferably, it is 2 μm or less. When the film thickness of the coating layer is too large, the emission intensity of the phosphor is lowered. If it is too small, the moisture resistance and gas barrier properties will be insufficient. The film thickness of the coating layer can be measured by any of the following methods (i) to (iii).
(I) Ten phosphor particles are arbitrarily selected with a scanning electron microscope (SEM), the film thickness is visually measured, and an average value is obtained.
(Ii) Phosphor particles arbitrarily selected using SEM-EDX (energy dispersive X-ray analysis) EPMA (electron probe, micro analysis), or a combination of SEM and CL (light emission by electron beam excitation) Elemental analysis of 10 cross sections is performed, the film thickness obtained is measured, and the average value is obtained.
(Iii) The difference between the median particle diameters D ₅₀ before and after the coating treatment is determined, and this is defined as the film thickness. However, when measuring the film thickness of the phosphor particles aggregated in the coating treatment of the present invention, measurement is performed after loosening the aggregation with ultrasonic waves or the like, or the above (i) or (ii) is adopted.
In the coated phosphor particles of the present invention, the coating layer formed by the glass composition is preferably a continuous film. Here, the continuous film means a state in which, when the coated phosphor particles are observed with a scanning electron microscope, the coating layer continuously covers the periphery of the phosphor and is not substantially torn.

[2-2] Combination of phosphor particles having good coverage and glass composition Among the phosphor particles described in [1-1] and [1-2], the coated phosphor described in [3] Nitride and / or oxide phosphor particles may be mentioned as those having good coverage by the particle production method.
A combination of phosphor particles and a glass composition is important for good coverage. That is, it is preferable that the wettability between the phosphor surface and the melt of the glass composition is good. Specifically, it preferably has the following properties.
(I) The contact angle of the glass composition in the molten state on the phosphor particle plane is usually 140 degrees or less, preferably 130 degrees or less, more preferably 120 degrees or less, usually 2 degrees or more, preferably 5 degrees. Above, more preferably 10 degrees or more.
(Ii) A chemical reaction occurs on the surface of the glass composition component and the phosphor particles.
(Iii) The reaction temperature of the chemical reaction does not affect the deterioration of the phosphor particles. That is, the reaction temperature is usually 800 ° C. or lower, preferably 600 ° C. or lower.

  A known method can be employed for measuring the contact angle. In measuring the contact angle, it is preferable to measure the average contact angle of the phosphor surface in the coating temperature and the clothing atmosphere. For example, by using “OCA 15 plus” manufactured by EKO, etc., the dynamic contact angle in the heated state is measured by the temperature control mechanism “TEC700”, etc., and the glass melt contacts the phosphor surface with the average value of the advance angle. It can be a corner.

  Examples of the combination of the phosphor particles having a good coating property and the glass composition include the following combinations.

  Further, from the viewpoint of the affinity between the phosphor particles and the glass composition, the zeta potential (mV) of the phosphor particles in water (pH 5.6) is usually −5 or less, preferably −10 or less, more preferably. -20 or less, particularly preferably -21 or less. On the other hand, the zeta potential (mV) of the glass composition in water (pH 5.6) is usually −50 or less, preferably −60 or less, and more preferably −50 or less. If the zeta potential of the glass composition is too large, the affinity with the phosphor particles may be lowered.

[3] Method for Producing Coated Phosphor Particles As a method for producing the coated phosphor particles of the present invention, for example, (A) phosphor particles, and (B) 1 selected from alkali metals, alkaline earth metals, and Zn are used. The glass composition containing the above can be mixed, and the method of heating above the yield point of the said (B) glass composition can be mentioned.
[3-1] Step of mixing (A) phosphor particles and (B) glass composition The particle size of (A) phosphor used in the present invention is as described in [1-4]. B) It is desirable that it is larger than the particle size of the glass composition. Although there is no restriction | limiting about the shape of the glass composition used for this invention, Usually, a granular and fibrous thing can be used. For example, when using a granular glass composition, the median particle size (D ₅₀ ) is usually 0.01 μm or more, preferably 0.1 μm or more, usually 20 μm or less, preferably 10 μm or less. The method for pulverizing the glass composition into a granular or powder form is not particularly limited, and pulverization with a mortar, vibration mill using media, ball mill, jet mill, planetary ball mill, and the like can be used.

When the phosphor particles are coated, it is preferable that the coating thickness is as thin as possible while keeping moisture resistance, in order to avoid light absorption by the film. From this point, the film thickness of the coating layer is usually 0.1 μm or more, preferably 0.5 μm or more, 10 μm or less, preferably 5 μm or less, and more preferably 2 μm or less. The film thickness of the coating layer can be measured by the same method as described in [2-1].
From the above points, the amount of the glass composition to be blended can be determined as the amount of the predetermined film thickness when the specific surface area of the phosphor particles is obtained and the continuous film is formed using the density of the glass composition.

  There is no limitation on the mixing method of the phosphor particles and the glass composition, but when the phosphor deteriorates against moisture, it is preferable to avoid the wet mixing method and adopt the dry mixing method. Examples of dry mixing methods include pulverization using a mortar and pestle, pulverization using a dry pulverizer such as a vibration mill, hammer mill, roll mill, ball mill, jet mill, etc., mixers such as a ribbon blender, V-type blender, Henschel mixer, etc. And a dry mixing method combining these. Examples of the combined dry mixing method include a combination of pulverization using a dry pulverizer and mixing using a mortar and a pestle, a combination of pulverization using a mixer and mixing using a mortar and pestle, and the like.

  At the time of mixing, the surface charge of the phosphor particles and the surface charge of the glass composition are not particularly limited, but it is preferable that at least one of the surface charges is a small value or a value that is not large. More preferably, they are different from each other. When the charges are different from each other, the glass composition easily adheres to the surface of the phosphor particles due to electrostatic attraction, and a good continuous film can be obtained during the subsequent heat treatment. The surface charge of the powder can be easily measured with a blow-off charge measuring device. In the case where the charges are the same, a method of changing the charges by surface-treating the phosphor particles as necessary may be used.

[3-2] Heating Step (A) The heating after mixing the phosphor particles and the (B) glass composition is not particularly limited as long as it is a method of heating above the yield point of the (B) glass composition. An example of the heating method is given below.
A mixture of phosphor particles and glass composition is filled into a less reactive crucible or tray. Although there is no restriction | limiting in particular in a container material, Quartz, an alumina, graphite, stainless steel, platinum, molybdenum, tungsten, silicon nitride, etc. can be used. Quartz is preferable in terms of thermal shock resistance, less contamination of the phosphor, and cost. Although there is no restriction | limiting in particular in the coating method by heat processing, In order to prevent adhesion of the fluorescent substance particles by glass, you may use the method heated in a fluid state. In order to improve the film formability, the glass particles may be uniformly adhered to the phosphor surface in advance. Specifically, a method of spray-drying a slurry made of glass particles and phosphor particles dispersed in a dispersion medium, a method of attaching glass particles to the phosphor surface using electrostatic adhesion, implantation by impact force, mechano Examples include a method of immobilizing glass particles on the surface of phosphor particles using a chemical reaction.

Further, when the phosphor and the glass powder are heat-treated, for example, in order to prevent adhesion between the glasses, the phosphor and the glass powder may be heated in a fluidized state or a rolling state.
The heating atmosphere varies depending on the type of phosphor particles. For a phosphor that deteriorates when heated in the air, it is preferable to employ an atmosphere in which deterioration does not occur.
Causes of deterioration due to heating include a change in the crystal matrix and / or a change in the valence of the luminescent center ion. The atmosphere is not particularly limited as long as the valence of the luminescent center ion does not change. However, for a phosphor containing the issuing center ion having a valence lower than the maximum oxidation number, such as Eu ²⁺ and Ce ³⁺ , an inert atmosphere. It is preferable to heat with. The oxygen concentration in the atmosphere is usually 100 ppm or less, preferably 20 ppm or less, more preferably 10 ppm or less. You may heat in the atmosphere at the time of manufacture of the fluorescent substance normally used. In addition, since the heating atmosphere may affect the affinity between the phosphor particles and the glass composition, a heating atmosphere in which the covering state is favorable is selected. In addition to the heating atmosphere, the moisture content of the glass powder and the phosphor powder may affect the coating state. Therefore, it is preferable to perform an appropriate pretreatment such as drying.

In order to coat the phosphor surface with glass and form a dense film, it is necessary to heat at a heating temperature equal to or higher than the yield point of the glass composition to be used.
The yield point is the temperature at which elongation stops and contraction begins.
The method for measuring the yield point is as follows.
Using a differential thermal dilatometer with a furnace temperature accuracy of ± 1 ° C., a sample (φ4 × 20 mm) is heated at a rate of temperature increase of 5 ° C. per minute, and the temperature and elongation of the glass are measured.
The heating time is a time required for mass transfer required for forming a film, and is maintained for a certain time after reaching a predetermined temperature. Usually 1 minute or longer, preferably 5 minutes or longer, usually 2 hours or shorter, preferably 0.5 hours or shorter.

[4] Characteristics of coated phosphor particles The coated phosphor particles of the present invention have the following characteristics. Due to the following characteristics, it is considered that the coated phosphor particles of the present invention are more sufficiently formed with a continuous film made of glass and have a higher gas barrier property than the conventional film forming method.

[4-1] Luminance and chromaticity Since the coating layer formed on the coated phosphor particles of the present invention has high light transmittance and is transparent in the UV-visible light region, the luminance and chromaticity of the phosphor particles before coating. Is hardly affected. Specifically, the luminance maintenance ratio of the coated phosphor particles with respect to the phosphor particles before coating of the present invention (luminance of the coated phosphor particles / luminance of the phosphor particles before coating × 100) is usually 70% or more, preferably Is 80% or more, more preferably 90% or more. The change in chromaticity is ± 0.05 or less in terms of CIE coordinates.

[4-2] Particle size distribution The coating layer formed on the coated phosphor particles of the present invention is a continuous thin film as described above, and the particle size distribution of the phosphor before coating treatment is hardly affected.
[4-3] Moisture resistance The coated phosphor particles of the present invention have high gas barrier properties, and no increase in weight is observed in the following high temperature and high humidity deterioration test.
[4-3-A] High-temperature and high-humidity deterioration test (i) The weight of the coated phosphor particles as a sample is measured.
(Ii) The coated phosphor particles are allowed to stand in a chamber maintained at an atmospheric temperature of 85 ° C./relative temperature of 85%.
(Iii) The weights of the coated phosphor particles after 200 hours and 400 hours are measured, and the respective weight increase rates are calculated by the following formulas.
Weight increase rate (%) = {measured weight in (iii)} / {measured weight in (i)} × 100
The reason why the coated phosphor particles of the present invention do not increase in weight in the high temperature and high humidity deterioration test is presumed as follows. That is, the conventional coating layer structure cannot prevent the permeation of water vapor, whereas the coating layer structure of the present invention does not have a void into which water vapor enters.

[5] Phosphor-containing composition The phosphor-containing composition of the present invention can be obtained by blending the coated phosphor particles of the present invention, a liquid medium, and other optional components. Hereinafter, the phosphor-containing composition will be described.
[5-1] Liquid medium As the liquid medium to be used, an inorganic material and / or an organic material can be used.
As the inorganic material, for example, a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof is solidified (for example, a siloxane bond). Inorganic materials having
Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, for example, methacrylic resin such as polymethylmethacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; Cellulose resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins. In particular, when a high-power light-emitting device such as illumination is required, it is preferable to use a silicon-containing compound for the purpose of heat resistance and light resistance.

  A silicon-containing compound is a compound having a silicon atom in the molecule, organic materials such as polyorganosiloxane (silicone-based materials), inorganic materials such as silicon oxide, silicon nitride, and silicon oxynitride, and borosilicates and phosphosilicates. Examples thereof include glass materials such as salts and alkali silicates. Among these, silicone materials are preferable from the viewpoint of ease of handling.

[5-1-1] Silicone material
The silicone-based material usually refers to an organic polymer having a siloxane bond as a main chain, and examples thereof include a compound represented by a general composition formula and / or a mixture thereof.
(R ¹ R ² R ³ SiO _1/2 ) _M (R ⁴ R ⁵ SiO _2/2 ) _D (R ⁶ SiO _3/2 ) _T (SiO _4/2 ) _Q
Here, the R ¹ R ⁶ may be the same or different, organic functional group, hydroxyl group, is selected from the group consisting of a hydrogen atom. M, D, T, and Q are 0 to less than 1 and satisfy M + D + T + Q = 1.
When a silicone material is used for sealing a semiconductor light emitting device, it can be used after being sealed with a liquid silicone material and then cured by heat or light.

[5-1-2] Types of silicone materials
When silicone materials are classified according to the curing mechanism, silicone materials such as an addition polymerization curing type, a condensation polymerization curing type, an ultraviolet curing type, and a peroxide vulcanization type can be mentioned. Among these, addition polymerization curing type (addition type silicone resin), condensation curing type (condensation type silicone resin), and ultraviolet curing type are preferable. Hereinafter, the addition type silicone material and the condensation type silicone material will be described.

[5-1-2-1] Addition type silicone material
The addition-type silicone material refers to a material in which a polyorganosiloxane chain is crosslinked by an organic addition bond. A typical example is a compound having a Si—C—C—Si bond at a crosslinking point obtained by reacting vinylsilane and hydrosilane in the presence of an addition catalyst such as a Pt catalyst. Commercially available products can be used. Specific examples of addition polymerization curing type trade names include “LPS-1400”, “LPS-2410”, and “LPS-3400” manufactured by Shin-Etsu Chemical Co., Ltd.

[5-1-2-2] Condensation type silicone material
Examples of the condensation type silicone material include a compound having a Si—O—Si bond obtained by hydrolysis and polycondensation of an alkylalkoxysilane at a crosslinking point.
Specific examples include polycondensates obtained by hydrolysis and polycondensation of compounds represented by the following general formula (1) and / or (2) and / or oligomers thereof.

M ^{m +} X _n Y ¹ _m-1 (1)

(In the formula (1), M represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. M represents one or more integers representing the valence of M, and n represents one or more integers representing the number of X groups, provided that m ≧ n.

^{_{(M s + X t Y 1}} s-t-1) u Y 2 (2)

(In the formula (2), M is silicon, aluminum, zirconium, and represents at least one element selected from titanium, X represents a hydrolyzable group, Y ¹ is a monovalent organic group Y ² represents a u-valent organic group, s represents an integer of 1 or more representing the valence of M, t represents an integer of 1 or more and s−1 or less, and u represents 2 or more. Represents an integer.)
Moreover, as a curing catalyst, a metal chelate compound etc. can be used suitably, for example. The metal chelate compound preferably contains one or more of Ti, Ta, and Zr, and more preferably contains Zr.

  A well-known thing can be used for a condensation type silicone type material, for example, Unexamined-Japanese-Patent No. 2006-77234, Unexamined-Japanese-Patent No. 2006-291018, Unexamined-Japanese-Patent No. 2006-316264, Unexamined-Japanese-Patent No. 2006-336010, The semiconductor light-emitting device members described in JP-A-2006-348284 and International Publication No. 2006/090804 are suitable.

Of the silicone materials, particularly preferred materials will be described below.
Silicone-based materials generally have a drawback of poor adhesion to semiconductor light-emitting elements, substrates on which the elements are arranged, packages, and the like, but as silicone-based materials having high adhesion, the following characteristics <1> to A silicone material having one or more of <3> is preferred.
<1> The silicon content is 20% by weight or more.
<2> The solid Si-nuclear magnetic resonance (NMR) spectrum measured by the method described in detail later has at least one peak derived from Si in the following (a) and / or (b).

(A) A peak whose peak top position is in a region where the chemical shift is −40 ppm or more and 0 ppm or less with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 3.0 ppm or less.
(B) A peak whose peak top position is in a region where the chemical shift is −80 ppm or more and less than −40 ppm with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 5.0 ppm or less.
<3> The silanol content is 0.01% by weight or more and 10% by weight or less.

  In the present invention, among the above features <1> to <3>, a silicone material having the feature <1> is preferable. More preferably, a silicone material having the above characteristics <1> and <2> is preferable. Particularly preferably, a silicone material having all of the above features <1> to <3> is preferable. Of the silicone materials having the above characteristics, a condensation type silicone material is preferable from the viewpoint of heat resistance, light resistance, and the like.

[5-1-3] Content of liquid medium The liquid medium is usually 50% by weight or more, preferably 75% by weight or more, and usually 99% by weight or less, based on the entire phosphor-containing composition of the present invention. Preferably it is 95 weight% or less.
When the amount of the liquid medium is large, no particular problem occurs. However, in order to obtain a desired chromaticity coordinate, color rendering index, luminous efficiency, etc. in the case of a semiconductor light-emitting device, the above-mentioned blending ratio is usually used. It is necessary to add a phosphor. If it is too small, it is difficult to handle because it is not fluid.
As described above, the liquid medium mainly has a role as a binder in the phosphor-containing composition of the present invention. Although a liquid medium may be used independently, multiple may be mixed. For example, when a silicon-containing compound is used for the purpose of heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the silicon-containing compound is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less based on the binder.

[5-2] Other ingredients
In addition to the above components, the phosphor-containing composition of the present invention comprises a phosphor other than the coated phosphor particles of the present invention, a thixotropic agent such as fumed silica, a dye, an antioxidant, and a stabilizer (phosphorous processing stability). Processing additives such as oxidizers, oxidation stabilizers, heat stabilizers, light-resistant stabilizers such as UV absorbers, etc.), light diffusing materials, fillers, etc. Can be used.

[5-3] Method for producing phosphor-containing composition
The method for producing the phosphor-containing composition of the present invention is not particularly limited as long as it is a method in which the coated phosphor particles of the present invention and other components added as necessary are uniformly dispersed in a liquid medium.
For example, the blending amount of the thixotropic agent is usually 0.1 parts by weight or more, preferably 0.3 parts by weight or more with respect to 100 parts by weight of the liquid medium. Moreover, it is 20 parts weight or less normally, Preferably it is 10 parts weight or less, More preferably, it is 5 parts weight or less. If the amount of the thixotropic agent is too small, the expected effect of suppressing the precipitation of the phosphor is not sufficient, and if it is too large, dispersion becomes difficult.
The amount of the phosphor containing the coated phosphor particles of the present invention is usually 0.01 parts by weight or more, preferably 0.1 parts by weight or more, more preferably 1 part by weight or more with respect to 100 parts by weight of the liquid medium. is there. Moreover, it is 100 parts weight or less normally, Preferably it is 80 parts weight or less, More preferably, it is 60 parts weight or less.

When a silicone resin is used as the liquid medium, for example, a silicone resin, a phosphor containing the coated phosphor particles of the present invention, a thixotropic agent, and a crosslinking agent, a curing catalyst, an extender, and other additives are blended. It can be produced by a conventionally known method such as mixing with a mixer, a high-speed disper, a homogenizer, a three-roller, a kneader or the like. In this case, all of the above components may be mixed to produce a liquid silicone resin composition in the form of one liquid,
Two liquids, (i) a silicone resin liquid mainly composed of a silicone resin, a phosphor and an extender, and (ii) a crosslinker liquid mainly composed of a crosslinking agent and a curing catalyst are prepared. A liquid silicone resin composition may be produced by mixing a resin solution and a crosslinking agent solution.

[5-4] Physical properties of phosphor-containing composition [5-4-1] Viscosity
The viscosity of the phosphor-containing composition of the present invention is usually 500 mPa · s or more, preferably 1000 mPa · s or more, more preferably 2000 mPa · s or more, and usually 15000 mPa · s or less, 10000 mPa · s or less, preferably 8000 mPa · s. s or less. If the viscosity is too high, it may cause trouble such as blockage of pipes at the time of injection, and bubbles may be difficult to escape, and further, lead wires of semiconductor elements are likely to be disconnected. On the other hand, if the viscosity is too low, the phosphor particles settle, which is not preferable.

  The phosphor-containing composition of the present invention preferably has thixotropic properties so that the phosphor-containing composition can be sufficiently filled (injected) into the light emitting device, and the phosphor does not settle before the liquid medium is cured after filling. . The thixotropic property can be confirmed by the fact that the viscosity at 1 rpm is larger than the viscosity at 5 rpm in the B-type viscometer when the rotor rotational speed is 1 rpm and 5 rpm.

[6] Light-emitting device The light-emitting device of the present invention is usually formed by a known method using the phosphor-containing composition described in [5]. Hereinafter, the light emitting device of the present invention will be described. Hereinafter, the coated phosphor particles of the present invention and the other phosphors will be simply referred to as “phosphors”.
[6-1] Light Source The light source in the light emitting device of the present invention emits light that excites the phosphor. The emission wavelength of the light source is not particularly limited as long as it overlaps with the absorption wavelength of the phosphor, and a phosphor having a wide emission wavelength region can be used. Usually, a phosphor having an emission wavelength from the near-ultraviolet region to the blue region is used, and specific numerical values are usually 300 nm or more, preferably 330 nm or more, and usually 500 nm or less, preferably 480 nm or less. A light emitter having the following is used. As this light source, a semiconductor light emitting element is generally used, and specifically, a light emitting diode (LED), a semiconductor laser diode (LD), or the like can be used.

  Among these, as the light source, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for the same current load, a GaN-based LED or LD usually has a light emission intensity 100 times or more that of a SiC-based. A GaN-based LED or LD preferably has an Al x Gay N light emitting layer, a GaN light emitting layer, or an In x Gay N light emitting layer. Among GaN-based LEDs, those having an InxGayN light-emitting layer are particularly preferred because the emission intensity is very strong, and in GaN-based LDs, those having a multiple quantum well structure of an InxGayN layer and a GaN layer have an emission intensity. It is particularly preferred because it is very strong.

In the above, the value of x + y is usually in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.
A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components. The light-emitting layer is sandwiched between n-type and p-type AlxGayN layers, GaN layers, or InxGayN layers. Those having the heterostructure are preferably high in luminous efficiency, and those having a heterostructure in the quantum well structure are further preferable because of higher luminous efficiency.

[6-2] Selection of phosphor In the light emitting device of the present invention, the presence / absence and the type of phosphor other than the coated phosphor particles of the present invention may be appropriately selected according to the use of the light emitting device.
When the light emitting device of the present invention is configured as a white light emitting device, one or more phosphors may be appropriately combined so as to obtain desired white light. When a blue light emitting element is used as a light source, it is preferable to use a yellow phosphor having a complementary color relationship of blue as a phosphor, and red and green phosphors to obtain white with higher color rendering properties. When using a semiconductor light emitting device that emits near-ultraviolet light, phosphors of three colors of red, green, and blue are preferably used.

Specifically, when the light-emitting device of the present invention is configured as a white light-emitting device, examples of preferable combinations of a light source and a phosphor include the following combinations (i) to (iii).
(I) A blue light emitter (blue LED or the like) is used as a light source, and a red phosphor and a green phosphor are used as phosphors.
(Ii) A near ultraviolet light emitter (near ultraviolet LED or the like) is used as a light source, and a red phosphor, a green phosphor and a blue phosphor are used in combination as phosphors.
(Iii) A blue light emitter (blue LED or the like) is used as a light source, and an orange phosphor and a green phosphor are used.

[6-3] Configuration of Light-Emitting Device The light-emitting device of the present invention is only required to include the above-described light source and the phosphor-containing composition of the present invention, and other configurations are not particularly limited. The above-mentioned light source and phosphor-containing composition are arranged on the top. At this time, the phosphor is excited by the light emission of the light source to generate light, and the light emission of the light source and / or the light emission of the phosphor is arranged to be taken out to the outside. In this case, the red phosphor does not necessarily have to be mixed in the same layer as the green phosphor and the blue phosphor. For example, the blue phosphor and the green phosphor are placed on the layer containing the red phosphor. The layer to contain may be laminated | stacked.

[6-4] Embodiments of Light-Emitting Device Hereinafter, the light-emitting device of the present invention will be described in more detail with reference to specific embodiments, but the present invention is not limited to the following embodiments. Any modifications can be made without departing from the scope of the present invention.

FIG. 1 is a diagram schematically showing a configuration of a light emitting device according to an embodiment of the present invention. The light emitting device 1 of the present embodiment includes a frame 2, a blue LED 3 that is a light source, and a phosphor-containing portion 4 that absorbs part of light emitted from the blue LED 3 and emits light having a wavelength different from that.
The frame 2 is a metal or resin base for holding the blue LED 3 and the phosphor-containing portion 4. On the upper surface of the frame 2, a trapezoidal concave section (dent) 2A having an opening on the upper side in FIG. Thereby, since the frame 2 has a cup shape, the light emitted from the light emitting device 1 can have directivity, and the emitted light can be used effectively. Further, the inner surface of the concave portion 2A of the frame 2 is enhanced in the reflectance of light in the entire visible light region by metal plating such as silver, so that the light hitting the inner surface of the concave portion 2A of the frame 2 can also be emitted. Can be discharged in a predetermined direction.

  A blue LED 3 is installed as a light source at the bottom of the recess 2 </ b> A of the frame 2. The blue LED 3 is an LED that emits blue light when supplied with electric power. Part of the blue light emitted from the blue LED 3 is absorbed as excitation light by the luminescent material (phosphor) in the phosphor-containing portion 4, and another part is directed from the light emitting device 1 in a predetermined direction. To be released.

In addition, the blue LED 3 is installed at the bottom of the recess 2A of the frame 2 as described above. Here, the frame 2 and the blue LED 3 are bonded to each other by the adhesive 5, so that the blue LED 3 is attached to the frame 2. is set up.
Further, a gold wire 6 for supplying power to the blue LED 3 is attached to the frame 2. That is, the electrode (not shown) provided on the upper surface of the blue LED 3 is connected by wire bonding using the wire 6, and when the wire 6 is energized, power is supplied to the blue LED 3. It emits blue light. One or a plurality of wires 6 are attached in accordance with the structure of the blue LED 3.

  Further, the concave portion 2A of the frame 2 is provided with a phosphor-containing portion 4 that absorbs part of the light emitted from the blue LED 3 and emits light having a different wavelength. The phosphor-containing part 4 is formed of a phosphor and a transparent resin. The phosphor is a substance that is excited by blue light emitted from the blue LED 3 and emits light having a wavelength longer than that of the blue light. The phosphor constituting the phosphor-containing portion 4 may be a single type or a mixture of a plurality, and the sum of the light emitted from the blue LED 3 and the light emitted from the phosphor light-emitting portion 4 is a desired color. Choose to be. The color is not limited to white, but may be yellow, orange, pink, purple, blue-green, or the like. Further, it may be an intermediate color between these colors and white. Further, the transparent resin is a sealing material for the phosphor-containing portion 4, and here, the above-described sealing material is used.

The mold part 7 functions as a lens for controlling the light distribution characteristics while protecting the blue LED 3, the phosphor-containing part 4, the wire 6 and the like from the outside. An epoxy resin can be mainly used for the mold part 7.
FIG. 2 is a schematic cross-sectional view showing an embodiment of a surface emitting illumination device incorporating the light emitting device 1 shown in FIG. In FIG. 2, 8 is a surface emitting illumination device, 9 is a diffusion plate, and 10 is a holding case.

This surface-emitting illuminating device 8 includes a plurality of light-emitting devices 1 on the bottom surface of a rectangular holding case 10 whose inner surface is light-opaque such as a white smooth surface, and a power source for driving the light-emitting device 1 on the outer side. And a circuit or the like (not shown). In order to make the light emission uniform, a diffusion plate 9 such as an acrylic plate made of milky white is fixed to a portion corresponding to the lid portion of the holding case 10.
Then, the surface-emitting illumination device 8 is driven to apply a voltage to the blue LED 3 of the light-emitting device 1 to emit blue light or the like. Part of the emitted light is absorbed in the phosphor-containing portion 4 by the phosphor of the present invention, which is a wavelength conversion material, and another phosphor added as necessary, and converted into light having a longer wavelength. Light emission with high luminance is obtained by mixing with blue light or the like that has not been absorbed. This light passes through the diffusion plate 9 and is emitted upward in the drawing, and illumination light with uniform brightness can be obtained within the surface of the diffusion plate 9 of the holding case 10.

  In the light-emitting device of the present invention, in particular, when a surface-emitting type is used as the excitation light source, it is preferable that the phosphor-containing portion is formed into a film. That is, since the cross-sectional area of the light from the surface-emitting type phosphor is sufficiently large, when the phosphor-containing portion is formed into a film shape in the direction of the cross-section, the irradiation cross-section area of the phosphor from the first phosphor is fluorescent. Since it becomes large per body unit quantity, the intensity | strength of light emission from fluorescent substance can be enlarged more.

  In addition, when a surface-emitting type light source is used as the light source and a film-like one is used as the phosphor-containing portion, it is preferable that the light-emitting surface of the light source is directly in contact with the film-like phosphor-containing portion. . Contact here means creating a state where the light source and the phosphor-containing portion are in perfect contact with each other without air or gas. As a result, it is possible to avoid a light amount loss in which light from the light source is reflected by the film surface of the phosphor-containing portion and oozes out, so that the light emission efficiency of the entire apparatus can be improved.

  FIG. 3 is a schematic perspective view showing an example of a light-emitting device using a surface-emitting type light source as a light source and applying a film-like one as a phosphor-containing portion. In FIG. 3, 11 is a film-like phosphor-containing portion having the phosphor, 12 is a surface-emitting GaN-based LD as a light source, and 13 is a substrate. In order to create a state where they are in contact with each other, the LD of the light source 12 and the phosphor-containing portion 11 may be formed separately, and their surfaces may be brought into contact with each other by an adhesive or other means. The phosphor-containing portion 11 may be formed (molded) on the light emitting surface. As a result, the light source 12 and the second phosphor-containing portion 11 can be brought into contact with each other.

[7] Use of light-emitting device The light-emitting device of the present invention can emit light of various colors depending on the type and amount of the phosphor used, but for lighting use, a light-emitting device that emits white light is useful. The light emitting device of the present invention has a luminous efficiency of usually 20 lm / W or higher, preferably 22 lm / W or higher, more preferably 25 lm / W or higher, particularly preferably 28 lm / W or higher, and an average color rendering index Ra of 80. Above, preferably 85 or more, more preferably 88 or more.

The average color rendering index Ra is calculated according to JIS Z 8726.
The light emission efficiency is calculated as follows by the product of the quantum absorption efficiency αq and the internal quantum efficiency ηi.
First, a phosphor sample to be measured (for example, powder) is packed in a cell with a sufficiently smooth surface so that measurement accuracy is maintained, and is attached to a spectrophotometer with an integrating sphere. Examples of the spectrophotometer include “MCPD2000” manufactured by Otsuka Electronics Co., Ltd. An integrating sphere or the like is used so that all the photons reflected from the sample and the photons emitted from the sample by photoluminescence can be counted, that is, photons that are not counted and fly out of the measurement system are eliminated.

  A light source for exciting the phosphor is attached to the spectrophotometer. This light emission source is, for example, an Xe lamp or the like, and is adjusted using a filter or the like so that the emission peak wavelength is 400 nm. The sample to be measured is irradiated with light from a light source adjusted to have a wavelength peak of 400 nm, and its emission spectrum is measured. In actuality, this measurement spectrum includes light from an excitation light source (hereinafter simply referred to as “excitation light”), photons emitted from the sample by photoluminescence, and excitation light reflected from the sample. Minutes of photon contributions overlap.

The quantum absorption efficiency αq is a value obtained by dividing the number of photons Nabs of the excitation light absorbed by the sample by the total number of photons N of the excitation light.
First, the total photon number N of the latter excitation light is obtained as follows. That is, a reflection plate such as a substance having a reflectance R of almost 100% with respect to excitation light, for example, “Spectralon” manufactured by Labsphere (having a reflectance of 98% with respect to excitation light of 400 nm) is measured. Is attached to the spectrophotometer and the reflection spectrum Iref (λ) is measured. Here, the numerical value obtained from the reflection spectrum Iref (λ) by the following (formula 1) is proportional to N.

Here, the integration interval may be substantially performed only in the interval where Iref (λ) has a significant value. The number of photons Nabs of the excitation light absorbed by the former sample is proportional to the amount obtained by the following (Equation 2).

Here, I (λ) is a reflection spectrum when a target sample for which the absorption efficiency αq is to be obtained is attached. The integration range of (Expression 2) is the same as the integration range defined in (Expression 1). By limiting the integration range in this way, the second term in (Equation 2) corresponds to the number of photons generated by the target sample reflecting the excitation light, that is, out of all photons generated from the target sample. This corresponds to the one excluding the photons generated by the photoluminescence by the excitation light. Since the actual spectrum measurement value is generally obtained as digital data divided by a certain finite bandwidth with respect to λ, the integrals of (Equation 1) and (Equation 2) are obtained by the sum based on the bandwidth.

From the above, αq = Nabs / N = (Expression 2) / (Expression 1).
Next, a method for obtaining the internal quantum efficiency ηi will be described. ηi is a value obtained by dividing the number NPL of photons generated by photoluminescence by the number Nabs of photons absorbed by the sample. Here, NPL is proportional to the amount obtained by (Equation 3) below.

    ∫λ · I (λ) dλ (Formula 3)

At this time, the integration interval is limited to the wavelength range of photons generated from the sample by photoluminescence. This is because the contribution of photons reflected from the sample is removed from I (λ). Specifically, the lower limit of the integration of (Expression 3) is the upper end of the integration of (Expression 1), and the upper limit is a range suitable for including a photoluminescence-derived spectrum.

Thus, ηi = (Expression 3) / (Expression 2) is obtained.
It should be noted that the integration from the spectrum that has become digital data is the same as when αq is obtained.
And the luminous efficiency defined by this invention is calculated | required by taking the product of quantum absorption efficiency (alpha) q calculated | required as mentioned above and internal quantum efficiency (eta) i.

  The application of the light-emitting device of the present invention is not particularly limited, and can be used in various fields where a normal light-emitting device is used. Moreover, you may use individually or in combination. Specifically, for example, it can be used as a light source for illumination lamps, backlights for liquid crystal panels, various illumination devices such as ultra-thin illumination, and image display devices. In addition, when using the light-emitting device of this invention as a light source of an image display apparatus, you may use together with a color filter.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, they are for the purpose of explaining the present invention, and are not intended to limit the present invention to these embodiments.
[1] _{Evaluation of} red phosphor Sr _0.792 Ca _0.2 AlSiN ₃ : Eu _0.008 [1-1] Example 1
Red phosphor particles {chemical composition Sr _0.792 Ca _0.2 AlSiN ₃ : Eu _0.008 (hereinafter sometimes referred to as “SCASN”), D ₅₀ = 8 μm} “PG325” manufactured by Sumita Optical Glass Co., Ltd., D ₅₀ = 8 μm, composition P ₂ O ₅ : 40 wt%, Li ₂ O: 5 wt%, LiF: 2 wt%, NaF: 10 wt%, K ₂ O: 3 wt% %, AlF3: 10% by weight, ZnO: 15% by weight, SrO: 10% by weight, CaO: 5% by weight, yield point 325 ° C.), 0.53 parts by weight, both are vibrated using a glass container. And mixed well. The obtained mixture is filled in a quartz container, and the quartz container is put into an electric furnace preheated to 400 ° C. in a nitrogen atmosphere having an oxygen concentration of 0.1 ppm or less and moisture of 0.1 ppm or less using an electric furnace. The mixture was heated for 10 minutes, cooled to 288 ° C., which was the glass transition temperature of the glass composition used, over 30 minutes, and held at 288 ° C. for 1 hour. Thereafter, it was cooled to room temperature to obtain powdered coated phosphor particles. About the covering fluorescent substance particle, the issue spectrum and the brightness | luminance were measured by the method as described in [1-1-1] and [1-1-2]. Further, when the obtained coated phosphor particles were observed with a scanning electron microscope, the phosphor particles were continuously coated with the glass composition layer. The film thickness of the coating layer was about 2 μm. Few particles of the glass composition alone without phosphor particles were observed. When the particle size distribution of the coated phosphor particles was measured, no aggregation of the particles was confirmed. In order to evaluate the denseness of the coating, the BET surface area was measured by the N ₂ adsorption method after heating at 250 ° C. for 30 minutes under a high-purity nitrogen flow. In order to test the gas barrier property, the phosphor powder was exposed to a chamber maintained at an atmospheric temperature of 85 ° C./relative humidity of 85%. The results are shown in Table 1.
[1-1-1] Emission spectrum At room temperature (25 ° C.), a fluorescence measurement apparatus (JASCO) equipped with a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a measurement apparatus. The measurement was performed using
Specifically, the light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 450 nm or more and 475 nm or less was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of excitation light is dispersed by a diffraction grating spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. An emission spectrum was obtained through signal processing such as sensitivity correction.
[1-1-2] Luminance Relative luminance is a blue phosphor (Ba, Eu) MgAl10017 (product number: manufactured by Kasei Optonix Co., Ltd.) based on the stimulation value Y in the XYZ color system calculated according to JIS Z8724. LP-B4) was calculated as a relative value (hereinafter sometimes simply referred to as “luminance”) with the stimulation value Y being 100%.
The luminance was measured by cutting excitation blue light.

Using the coated phosphor particles obtained, a light-emitting device was produced by the following procedure.
An LED chip “C460-EZ290” (emission wavelength: 461 nm) manufactured by CREE was bonded to an SMD LED package “TY-SMD1202B” manufactured by Toyo Denki.
Silicone resin “SCR-1011” manufactured by Shin-Etsu Chemical Co., Ltd. and a curing agent are mixed in a ratio of 100 parts by weight: 100 parts by weight, and 0.8 part by weight of a red phosphor is added to 100 parts by weight of the mixture. The phosphor-containing composition was kneaded for 3 minutes with a stirrer “Awatori Netaro AR-100”.

This composition was filled to the uppermost surface of the package with the LED chip, and heat-cured at an ambient temperature of 70 ° C. for 1 hour and then at an ambient temperature of 150 ° C. for 5 hours.
The obtained light-emitting device was driven at 20 mA at room temperature (about 25 ° C.), and CIE chromaticity coordinates x were measured.
Next, the light emitting device was subjected to a current test of 20 mA, 100 hours, and 250 hours under high temperature and high humidity conditions of an ambient temperature of 85 ° C. and 85% RH, and the CIE chromaticity coordinate x was measured in the same manner.
And the ratio (x maintenance factor:%) of the chromaticity coordinate x after high-temperature, high-humidity exposure 100 hours and 250-hour progress with respect to the chromaticity coordinate x immediately after manufacture of the said light-emitting device was calculated, and a result is shown in Table 1. It was.

[1-2] Example 2
The coated phosphor particles were produced in the same manner as in Example 1 except that the amount of the glass composition was 1.06 parts by weight, and each evaluation other than the specific surface area measurement and the x maintenance factor was performed. The film thickness of the coating layer was about several μm. The results are shown in Table 1.
[1-3] Comparative Example 1
Each evaluation other than the film shape observation was performed in the same manner as in Example 1 except that SCASN was used as it was. The results are shown in Table 1.
[1-4] Comparative Example 2
3 g of SCASN was placed in a 50 ml flask, and 20 ml of ethanol was added and stirred. Next, 6.7 g of 28% ammonia water manufactured by Kishida Chemical Co., Ltd. was added and stirred with a magnetic stirrer for 1 minute. Next, 20 mL of tetraethoxysilane (hereinafter referred to as “TEOS”) was gradually added in two portions while stirring vigorously with a magnetic stirrer, and subsequently stirred with a magnetic stirrer for 90 minutes. The resulting solution was allowed to stand for 3 minutes, and then the supernatant was removed with a dropper or the like.

Thereafter, 30 mL of ethanol was added, stirred for 1 minute, and allowed to stand for 3 minutes. Supernatant removal was repeated until the supernatant became colorless and transparent. The obtained sediment was dried under reduced pressure at 150 ° C. for 2 hours with a vacuum dryer to obtain a surface-treated phosphor. The surface-treated phosphor had a silicon oxide film of 12% by weight based on the weight of the phosphor. The film thickness was about 100 nm.
The coated phosphor particles obtained above were evaluated in the same manner as in Example 1 except for the x retention rate. The results are shown in Table 1.

[1-5] Comparative Example 3
Soda lime glass (SiO ₂ 70 wt%, Al ₂ O ₃ 2 wt%, Na ₂ O 13 wt%, CaO 10 wt%, MgO 4 wt%, and K ₂ O and Fe ₂ O ₃ , SO ₃
Etc. (including <1% by weight), etc., using an alumina mortar, and the median particle size D ₅₀
= About 8 μm. The glass transition point is in the vicinity of 730 ° C., and the yield point is in the region of 700 ° C. to 750 ° C. A glass-coated phosphor was produced in the same manner as in Example 1 except that this glass powder was used, the coating temperature was set to 750 ° C., and the glass transition temperature was not maintained, and specific surface area measurement, weight increase rate and x maintenance were performed. Each evaluation other than rate was performed. The results are shown in Table 1.

  The specific surface area of Example 1 was smaller than the specific surface area of SCASN of Comparative Example 1 which was not coated. On the other hand, the specific surface area of SCASN of Comparative Example 2 coated with tetraethylorthosilicate was larger than the specific surface area of SCASN of Comparative Example 1 which was not coated. This indicates that the coating layer of Example 1 has a very high density on the surface of SCASN. On the other hand, the coating layer of Comparative Example 2 shows a relatively low-density shape in which fine particles are deposited. This was confirmed also by the observation result of the scanning electron microscope. That is, the coating layers of Examples 1 and 2 were observed as a smooth continuous film in which the glass composition was sufficiently melted, whereas in the conventional method of Comparative Example 2, the coating layer was an aggregate of silica fine particles. The structure was observed.

Moreover, the weight of SCASN of Comparative Example 2 was increased, and as a result of XRD measurement, strontium carbonate was confirmed. This is presumed that SCASN was hydrolyzed under high temperature and high humidity conditions and reacted with carbon dioxide in the atmosphere to produce strontium carbonate. In contrast, the coated phosphor particles of Examples 1 and 2 did not increase in weight until at least 400 hours, and the glass-coated film of the coated phosphor of the present invention has extremely high gas barrier properties against water, carbon dioxide and the like. It was shown to have. Furthermore, when the reliability evaluation under the high temperature and high humidity conditions was performed with the light emitting device, in the light emitting device using the SCASN-coated phosphor particles of Example 1, the color shift of the emitted color (change in Cx value) was at least. It was not observed at all until 250 hours. On the other hand, in the case of Comparative Example 1 where no coating was performed, a 2% decrease in Cx value was observed in 250 hours.
In Comparative Example 3, a sufficient coating layer was not formed, and the luminance of SCASN was lowered. It was speculated that the decrease in luminance was caused by the coating treatment at a high temperature.

[2] Evaluation of green phosphor Ba _1.39 Sr _0.46 Eu _0.15 SiO ₄ [2-1] Example 3
Green phosphor particles {Ba _1.39 Sr _0.46 Eu _0.15 SiO ₄ (hereinafter sometimes referred to as “BSS”), D ₅₀ = 21 μm} The glass composition (Sumida Optical Glass) relative to 1 part by weight Coated phosphor particles were obtained in the same manner as in Example 1 except that 0.75 part by weight of “PG325” manufactured by the company was used. The film thickness of the coating layer was about several μm. Each evaluation similar to Example 1 was performed.
In addition, after 0.1 g of the coated phosphor powder was dispersed in 50 g of pure water at room temperature, the electric conductivity after standing for 1 hour was 26.7 μS / cm. The results are shown in Table 2.

[2-2] Example 4
Each evaluation was performed by performing the same treatment as in Example 3 except that 1 part by weight of the glass composition (“K-PG325” manufactured by Sumita Optical Glass Co., Ltd.) was used. The film thickness of the coating layer was about several μm. The results are shown in Table 2.
[2-3] Comparative Example 4
Each evaluation other than the film shape observation was performed in the same manner as in Example 3 except that BSS was used as it was. The results are shown in Table 2.

[2-3] Comparative Example 5
In a 500 mL flask, 50 g of TEOS with a purity of 95% or more and 224 g of ethanol with a purity of 99.5% with a purity of 99.5% were added and mixed uniformly to prepare a metal alkoxide solution.
In a 1 L separable flask with a jacket, 310 g of ethanol, 100 g of high-grade purity 28% ammonia water manufactured by Kishida Chemical Co., Ltd. were added and mixed uniformly.
g A substrate phosphor containing solution was prepared by charging.

A temperature-controlled cooling water is allowed to flow through the jacket of the separable flask to keep the temperature of the reaction solution constant at 5 ° C., and the substrate phosphor-containing solution is vigorously stirred with a stirring blade equipped with a motor so that the BSS powder does not settle. Then, the metal alkoxide solution was dropped into the BSS powder with a metering pump over about 4 hours.
After the dropping of the metal alkoxide solution was completed, the reaction solution was allowed to stand to settle the green phosphor, and then the liquid phase clouded with silica fine particles was removed by decantation. Thereafter, 500 mL of ethanol was added, and the mixture was lightly stirred and allowed to stand, and the liquid layer with white turbidity was removed by decantation. This ethanol washing is repeated 4 times until the liquid layer becomes colorless and transparent, and the separable flask is dried under reduced pressure at 50 ° C. for 30 minutes, and then dried at 150 ° C. for 2 hours to obtain a silica adhesion rate of 24.0. A BSS phosphor powder coated with silica on the surface by weight was obtained. The film thickness was about 150 to 200 nm.
The coated phosphor particles obtained above were evaluated in the same manner as in Example 3. The results are shown in Table 2.

[2-4] Comparative Example 6
A glass-coated phosphor was produced in the same manner as in Example 3 except that the glass powder obtained in Comparative Example 3 was used, the coating temperature was set to 750 ° C., and the glass transition temperature was not maintained, and a glass-coated phosphor other than the specific surface area was produced. Each evaluation was performed. The results are shown in Table 2.
[2-5] Comparative Example 7
A glass-coated phosphor was produced in the same manner as in Example 3 except that the glass powder obtained in Comparative Example 3 was used, the coating temperature was set to 850 ° C., and the glass powder was not held near the glass transition temperature. Each evaluation was performed. The results are shown in Table 2.

  In the green phosphor BSS, the same result as that of the red phosphor SCASN was obtained. Moreover, since the electrical conductivity of Example 1 and 2 is lower than that of the comparative example 4, it was confirmed that the ion elution derived from a BSS fluorescent substance is suppressed.

The coated phosphor particles and the phosphor-containing composition of the present invention have good gas barrier properties without aggregation of the phosphor, and can improve the durability of the semiconductor light emitting device. In addition, the light-emitting device of the present invention, and the image display device and the lighting device using the light-emitting device can be used for a long time and have high durability because they have excellent durability.
Therefore, the coated phosphor particles, the method for producing the coated phosphor particles, the phosphor-containing composition, the light emitting device, the image display device, and the lighting device of the present invention have extremely high industrial applicability in each field.

It is typical sectional drawing which shows one Example of the light-emitting device of this invention. It is typical sectional drawing which shows an example of the surface emitting illumination apparatus using the light-emitting device of this invention. It is a typical perspective view which shows other embodiment of the light-emitting device of this invention.

Explanation of symbols

1 Light-emitting device
2 frames
2A Concave part of the frame
3 Blue LED (first light emitter)
4 Phosphor-containing part (second light emitter)
5 Adhesive 6 Wire
7 Mold part
8 Surface emitting lighting device
9 Diffusion plate
10 Holding case
11 Phosphor content part
12 Light source
13 Substrate

Claims (11)

  (A) A phosphor particle coated with (B) a glass composition containing one or more selected from alkali metals, alkaline earth metals and Zn, wherein (B) the glass composition A coated phosphor particle having a yield point of 700 ° C. or lower.   (A) A phosphor particle coated with (B) a glass composition containing one or more selected from alkali metals, alkaline earth metals and Zn, wherein (B) the glass composition The coated phosphor particles, wherein the coating layer formed by has a thickness of 0.1 μm or more and 10 μm or less.   The coated phosphor particle according to claim 1 or 2, wherein the phosphor particle (A) is a nitride and / or an oxide. The coated phosphor particle according to any one of claims 1 to 3, wherein the (B) glass composition contains the following (I) and (II).
(I) Glass formation with Zachariasen comprising one or more selected from SiO ₂ , B ₂ O ₃ , P ₂ O ₅ , GeO ₂ , TeO ₂ , Al ₂ O ₃ , Ga ₂ O ₃ , and Bi ₂ O ₃ Oxide (II) Network-modified oxide containing one or more selected from alkali metal atoms, alkaline earth metal atoms, and Zn   The coated phosphor particles according to any one of claims 1 to 4, wherein a content of lead in the glass composition (B) is 0.1% by weight or less. The coated phosphor particle according to any one of claims 1 to 5, wherein the coating layer formed by the (B) glass composition is a continuous film.   (A) Phosphor particles, and (B) a glass composition containing one or more selected from alkali metals, alkaline earth metals and Zn are mixed and heated above the yield point of the (B) glass composition. The manufacturing method of the covering fluorescent substance particle characterized by the above-mentioned.   A phosphor-containing composition comprising the coated phosphor particles according to claim 1.  The light-emitting device formed using the covering fluorescent substance particle of any one of Claims 1-6.   An image display device comprising the light-emitting device according to claim 9 as a light source.   An illumination device comprising the light-emitting device according to claim 9 as a light source.

Images